The following relates to the phosphor arts, wavelength conversion arts, and related arts, and to optoelectronic, photonic, and like applications using same such as (but not limited to) projection displays (e.g. digital light processing, DLP), automotive lighting, and so forth.
Phosphor elements are known for converting light wavelength, usually down-converting from a shorter wavelength to one or more longer wavelengths. In a common approach, phosphor materials are dispersed in a transparent or translucent binder material such as epoxy, silicone, or so forth, which is then cured to form a solid phosphor element. The phosphor element is energized, or “pumped” by a laser, light emitting diode (LED), or other pump light source to emit phosphorescence. The phosphor element may be static, i.e. not moving during operation. In another application, the phosphor element is mounted near the outer rim of a rotating wheel (i.e. a phosphor wheel device), which effectively distributes heating from the pump beam over a larger area. A phosphor wheel device also advantageously can provide a time sequence of different colors (or more generally different phosphorescence spectra) by using different phosphors in different phosphor elements (i.e. different arc segments) disposed along the rim of the phosphor wheel. Periods of zero emission can also be provided by leaving arced gaps between neighboring phosphor arc segments. Such a phosphor wheel can be used, for example, to provide sequential red, green, and blue light for a Digital Light Processing (DLP) projector or other DLP display device.
Some improvements are disclosed herein.